Configurable solar cells

ABSTRACT

A photovoltaic cell may include a substrate configured as a single light absorption region. The photovoltaic cell may include a plurality of first semiconductor regions arranged on or in the substrate and physically separated from one another. Each first semiconductor region may form one of a plurality of collecting junctions with the single light absorbing region. The photovoltaic cell may include a plurality of second semiconductor regions arranged on or in the substrate and physically separated from one another. Each second semiconductor region forming one of a plurality of high-low junctions with the single light absorbing region. Each of the first semiconductor regions may form at least one separate cell partition with at least one of the second semiconductor regions, thereby forming a plurality of cell partitions on or in the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from U.S. Provisional Application No. 62/677,934, entitled “ELECTRICAL POWER FLOW AND CONFIGURABLE POWER OUTPUT FOR PHOTOVOLTAIC CELLS WITH A COMMON ABSORBER REGION AND A PLURALITY OF PARTITIONED COLLECTING JUNCTIONS,” filed May 30, 2018, the entirety of which is incorporated by reference herein

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a semiconductor wafer with cell partitions according to an embodiment of the disclosure.

FIG. 2 is a cross-sectional view of a semiconductor wafer with interconnected cell partitions according to an embodiment of the disclosure.

FIG. 3 is a cross-sectional view of a semiconductor wafer with interconnected cell partitions according to an embodiment of the disclosure.

FIG. 4 is a cross-sectional view of a semiconductor wafer indicating possible device behavior according to an embodiment of the disclosure.

FIGS. 5A and 5B show a structure according to an embodiment of the disclosure.

FIG. 6 is a cross-sectional view of a semiconductor wafer with cell partitions according to an embodiment of the disclosure.

FIG. 7 is a cross-sectional view of a semiconductor wafer with cell partitions using passivated emitter and rear contact (PERC) photovoltaic cell technology according to an embodiment of the disclosure.

FIG. 8 is a cross-sectional view of a semiconductor wafer with cell partitions using interdigitated back contact (IBC) architecture according to an embodiment of the disclosure.

FIG. 9 is a plan view of a multi-cell panel with strings of cells in parallel according to an embodiment of the disclosure.

FIG. 10 is a plan view of a multi-cell panel with cell details according to an embodiment of the disclosure.

FIG. 11 is a diagram of a roof shingle according to an embodiment of the disclosure.

FIG. 12 is a plan view of a multi-cell panel with cell details according to an embodiment of the disclosure.

FIG. 13 is a plan view of a multi-cell panel with cell details according to an embodiment of the disclosure.

FIG. 14 is a diagram of a multi-panel system according to an embodiment of the disclosure.

FIG. 15 is a plan view of a multi-cell panel with cell details according to an embodiment of the disclosure.

FIG. 16 shows plan views of multi-cell panels with cell details according to an embodiment of the disclosure.

FIG. 17 shows plan views of multi-cell panels with cell details according to an embodiment of the disclosure.

FIGS. 18A-18B show cross-sectional views of thin film panels according to embodiments of the disclosure.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

Some embodiments of the disclosed technology may enable the design, manufacturing, and production of semiconductor wafer photovoltaic cell(s) with configurable output voltage and output current characteristics (“power characteristics”) on a single, physically contiguous light absorbing wafer/substrate. Some embodiments of the disclosed technology may enable configurable power characteristics by creating multiple semi-electrically isolated collecting junctions on a single light absorbing wafer and electrically interconnecting the collecting junctions in series and/or parallel circuits, for example. Some embodiments of the disclosed technology may enable a plurality of physically isolated wafers, some or all with configurable power characteristics, to interconnect in a photovoltaic panel, module, or system, for example.

Configurable Voltage Cell (CVC) Structure

FIG. 1 is a cross-sectional view of a semiconductor wafer 100 with cell partitions 120 according to an embodiment of the disclosure. Wafer 100 may be configured as a photovoltaic device, including base or light absorber region 102, emitter region 104, and back surface field region 106. Base region 102 and emitter region 104 may define a collector junction 105 therebetween. Base region 102 and back surface field region 106 may define a high-low junction 107 therebetween. In wafer 100, cell partitions 120 may be defined by one or more functionally partitioned emitter(s) 104 with matching back surface field region(s) 106 on a single, physically contiguous light absorbing wafer/substrate 102. FIG. 1 illustrates two partitions 120, where each partition 120 is defined by separate overlapping collecting junction 104 and high-low junction 106 pairs.

Base region 102, emitter region 104, and back surface field region 106 may be semiconductor regions that are doped differently from one another to encourage photovoltaic activity therebetween. For example, as shown in FIG. 1, base region 102 may be made of a p type material, emitter region 104 may be made of an n+ type material, and back surface field region 106 may be made of a p+ type material. However, in other embodiments, the regions may be configured differently. For example, in some embodiments, base region 102 may be made of a p type material, emitter region 104 may be made of a p+ type material, and back surface field region 106 may be made of an n+ type material. In some embodiments, base region 102 may be made of an n type material, emitter region 104 may be made of an n+ type material, and back surface field region 106 may be made of a p+ type material. In some embodiments, base region 102 may be made of an n type material, emitter region 104 may be made of a p+ type material, and back surface field region 106 may be made of an n+ type material.

Wafer 100, and other wafers described herein, may be regarded as a single photovoltaic cell in some embodiments. Wafer 100 may be configured using a photovoltaic cell technology such as aluminum back surface field (Al-BSF). For example, in addition to base/light absorber region 102, emitter regions 104, and back surface field regions 106, wafer 100 may include back aluminum (or other conductive material) contacts 112 which may be functionally partitioned corresponding to each partitioned back surface field region 106. Wafer 100 may include an anti-reflective coating 108 which may be partitioned or may be continuous. Wafer 100 may include front silver (or other conductive material) bus bars 110, each corresponding to a separate emitter region 104 and/or rear silver (or other conductive material) bus bars 114, each corresponding to a separate back surface field region 106.

The partitions 120 may share a common base/bulk region which may serve as light absorber region 102. The common light absorber region (base/bulk region) 102 may maintain the physical connection for the isolated partitions 120. FIG. 1 demonstrates one embodiment that semi-electrically isolates partitions 120 by leaving an undoped bulk material region 122, and/or non-silicon region such as an edge and/or airgap, between partitions 120. Other embodiments may provide improved performance for series connected partitions 120 by configuring the depth and width of the regions 122 between partitions 120. Wafer 100, with its two partitions 120, may generate twice the output voltage and half the output current of a wafer configured similarly but lacking isolated partitions 120, for example. As described in detail below, individual wafers 100 (and/or other wafers described herein) may be incorporated into multi-cell panels (e.g., panel 1200 of FIG. 9 and other panels described below).

FIG. 2 is a cross-sectional view of a semiconductor wafer 300 with interconnected cell partitions 120 according to an embodiment of the disclosure. Some embodiments may interconnect multiple partitions 120 using a variety of conducting and/or semiconducting materials in a series and/or parallel circuit to create a photovoltaic cell wafer 300 with configurable power characteristics (“Configurable Voltage Cell” or “CVC”). For example, wafer 300 includes partitions 120 interconnected by a plurality of interconnects 302. Partitions 120 may be interconnected with interconnects 302 made from copper wire, tin-coated copper wire, silver, silver paste, evaporated metals, etc. In the example of FIG. 2, two partitions 120 are connected/interconnected in series between positive terminal 304 and negative terminal 306 to generate twice the standard output voltage and half the standard output current (e.g., measured at terminals 304 and 306) of a photovoltaic (“PV”) cell that does not utilize the disclosed technology (e.g., wafer 200). For example, the two partitions 120 of wafer 300 may produce power characterics of approximately 4.95 Watts, a voltage output of approximately 1.1 volts, and approximately 4.5 amps of output current. This configuration of partitions 120 may create approximately 2 times the voltage output and one-half the current output of a cell lacking partitions under similar conditions.

FIG. 3 is a cross-sectional view of a semiconductor wafer 400 with interconnected cell partitions according to an embodiment of the disclosure. Wafer 400 of FIG. 3 is similar to wafer 300 of FIG. 2, so some reference numbers are omitted for ease of understanding the drawing. Wafer 400 is configured in the same manner as wafer 300, but with nine partitions instead of two. Accordingly, wafer 400 may produce 9-times the standard output voltage and one-ninth the standard current at terminals 304 and 306.

FIGS. 2 and 3 provide example configurations for wafers and interconnections, but many other configurations may be possible. Specifically, FIG. 2 shows series connected partitions, on a common base/bulk wafer/substrate (light absorber region), for an output voltage of 2 times a standard Al-BSF crystalline silicon PV cell with one pn collecting junction and one-half the standard output current. A singular collecting junction on a singular semiconductor wafer/substrate may represent a photovoltaic cell (“Standard PV Cell”). A first partition may be connected to a second partition, where the output power may be measured between the first partition and the second partition. Any multiple of partition on a common base/bulk (light absorber region) may be realized by repeating the methodology. For example, FIG. 3 shows 9 partitions on a common light absorber where a series connection for all 9 partitions may produce the output voltage of 9 times a Standard PV Cell and 1/9 the output current of a Standard PV Cell. One embodiment of the technology may create the same Al-BSF cell on a 6 inch pseudo square wafer with a power output of approximately 4.95 Watts and may have an output voltage 4.95 volts (9 multiplied by 0.55 V), and an output current of 1 Amp (9 amps divided by 9). Any number of partitions may be designed with some consideration to material constraints and process limitations. The disclosed technology may also be used in a parallel configuration for the preceding example of 9 partitions on a singular common light absorber (base/bulk) (e.g., by applying interconnects 302 to bus bars 110 and 114 in a parallel, rather than series, arrangement) and may produce the output voltage of approximately 0.55 V (max power point voltage) and output current of approximately 9 amps (max power point current) similar to the standard contiguous pn junction and contiguous BSF on the common base/bulk (light absorber region). The disclosed technology may function/operate or perform as the existing standard technology and/or may function/operate or perform with partitions that may be controlled by the designer (e.g., selecting the number of partitions and how they are configured, in series and/or parallel) to yield desired power characteristics

FIG. 4 is a cross-sectional view of a semiconductor wafer 500 indicating possible device behavior according to an embodiment of the disclosure. The disclosed technology may create a plurality of options for the way externally generated current flows through the partitions on a CVC. The configuration of one or more connection/interconnection(s) between CVC(s) may cause external current to fully/partially flow as if the CVC is a simple diode/transistor/semiconductor/etc. and not as a photovoltaic generator. For example, in FIG. 4, if positive terminal 502 and negative terminal 504 are provided as shown, measurements made therebetween may function as an npn transistor in addition to a photovoltaic generator, which may be undesirable for some applications. This may be compared with embodiments wherein partitions are wired in series on the CVC (e.g., see FIG. 3), where external current may be connected to the first partition in a series of connected partitions and exited on the last partition to achieve the desired power characteristics. In embodiments with partitions wired in a combination of series and parallel, the external current may be connected to the first partition in each of the series of parallel connected partitions and exited on the last in a series of parallel connected partitions. The method of interconnection/connection may be either in series or parallel and may be designed such that an alternative electrical path may be eliminated so as to restrict the flow of electrical current on a common light absorber so that it does not suffer a parasitic resistance path and/or a competing electrical current flow (e.g., as in FIG. 4).

In various embodiments, power characteristics may scale proportional to the number of partitions and the series and/or parallel configuration of partitions. Any multiple of partitions may be configured to create the desired power characteristics such as 2, 3, 4 times, . . . , 20 times, etc. the output voltage of a wafer without partitions with the corresponding output current of one-half times, one-third times, one-fourth times, . . . , 1/20 times, etc. The disclosed technology may be applied to photovoltaic cell technology including, but not limited to, crystalline silicon technologies such Aluminum Back Surface Field (Al-BSF), Passivated Emitter and Rear Contact (PERC), Bifacial, Heterojunction Technology (HJT), Interdigitated Back Contact (IBC), Emitter Wrap Through (EWT), etc.

The disclosed technology may be applicable across various substrates that may be used/partially used as a light absorption layer/region. First generation photovoltaic cells may be considered semiconductor wafer based technologies. The examples provided herein for reference or clarification often cite the use of crystalline silicon wafers as the base substrate used in a photovoltaic cell. However, the disclosed technology may be applicable to, and compatible with, a wide variety of semiconductor materials as the base material including, but not limited to, crystalline Si, multi-crystalline silicon, mono-crystalline silicon, mono-like crystalline silicon, Ge, SiGe, amorphous silicon, so called III-V semiconductor materials, II-VI materials, amorphous silicon, SiC, etc.

CVC Design

The disclosed technology may improve the flexibility in designing the size, shape, and thickness used to fabricate photovoltaic devices. By configuring the power characteristics associated with a particular semiconductor wafer/substrate, as disclosed herein, it may be possible to increase and/or decrease the length, width, and thickness of the substrate. Additionally, some embodiments may allow for the creation of semiconductor wafer/substrates of irregular shapes and sizes that have configurable power characteristics. For example, the following embodiments illustrate example features made possible through creating semiconductor wafer(s)/substrate(s) with configurable power characteristics that vary from industry standard 5 and/or 6 inch square/pseudo square wafers.

One example embodiment may enable the creation of large wafers. Many substrates/wafers used in the photovoltaic industry are 6 inch crystalline silicon pseudo square/square wafers, because larger wafers without partitions may exhibit high output current resulting in hot spots and undesirable resistive losses. However, wafers configured as described herein may exhibit desirable power characteristics for large wafers exceeding 6 inch squares. For example, the disclosed technology may enable the creation of an 8 inch, 10 inch, 12 inch, etc. square wafer with any number of configurable partitions creating the desired power characteristics. By creating multiple partitions, resulting in higher voltage output and lower current output, the undesirable power characteristics of high output current which may result in hot spots and resistive losses may be mitigated and/or avoided.

For example, an 8 inch wafer with 2 partitions in series may output approximately 1.1 V and approximately 8.6 amps. In another example, 20 partitions may be configured in series to output approximately 11 V and approximately 0.86 amps. This embodiment may enable the production of fewer wafers in each PV panel/module, smaller conductors, reduction and/or elimination of the need for bypass diodes, more active area per panel, elimination or reduction of hotspots, increase in overall power output, reduction in costs, and/or reduction in potential points of failure created by inclusion of electronics. These desirable power characteristics and other benefits may apply to a CVC, a CVC Panel, and/or a complete system.

One example embodiment may enable configurable power characteristics on wafers of any shape and/or size. By configuring a multitude of partitions, in series and/or parallel, on any shape/size wafer, the disclosed technology may enable the configuration of power characteristics such that they match the power characteristics of Standard PV Cells and/or CVC(s). For example, the disclosed technology may enable an installer of residential roof top photovoltaic panels/modules to cover additional roof surface area(s) that are irregular size or shape. FIGS. 5A and 5B show a structure 600 according to an embodiment of the disclosure. Structure 600 includes roof 602 with a non-rectangular surface area. Irregular shaped photovoltaic cells and/or photovoltaic panels 604 may provide complete coverage and an aesthetically pleasing appearance. Wafers/panels configured according to the embodiments described herein may have irregular shapes and/or may be configured to have power characteristics matching the power requirements of adjacent panels 606 and/or Standard Cells and/or CVC(s). In some embodiments, disclosed photovoltaic panels may fill the maximum available space on small, non-uniform surfaces like automobiles and spacecraft while supporting desired power characteristics.

Many electric and/or electronic devices may require specific power characteristics like 5V or 12V. The disclosed technology may be used to produce power characteristics configured to directly match the voltage/current requirements for a wide variety of electrical and/or electronic devices requiring specific power requirements, thereby reducing waste, increased labor efforts, weight, and/or points of failure as opposed to breaking PV cells into small pieces and/or using DC to DC converters. For example, the number of partitions, in series and/or parallel, on a one inch square wafer may be designed to produce an output voltage of 5 V, enabling the wafer to directly supply power to a higher voltage device such as a mobile phone or battery charger. In another example, the number of partitions may be configured to produce 12 V to drip charge a battery or a car directly.

The disclosed technology may reduce/limit power (I2R) loss. For example, the amount of I2R loss and/or heat loss for a standard 60 cell photovoltaic panel may be approximately 8 Watts when the output current is 9 amps. The heat loss may then follow PLoss=I2R, where 8 Watts=81R. Therefore the resistance of the system, R, is 0.1 ohms. One embodiment of the disclosed technology may configure partitions, in series and/or parallel, to produce power characteristics of one half the output current, approximately 4.5 A, and two times the output voltage of 66 V. Thus, PLoss=(4.5 amps)2(0.1 ohms)=2 Watts. This may represent a reduction of loss of approximately 6 Watts for an approximately 300 Watt panel. Additionally, this embodiment may reduce the size of the wire/conductor required to connect/interconnect CVC and/or other semiconductor wafers.

The disclosed technology may produce power characteristics on a CVC such that metal contacts (metallization) used to transport the electrons collected from photons (absorbed light) may be small and/or thin. Small metalization and/or conductors may decrease the cost of metal and may increase the exposed surface area on the wafer.

CVC Production

The production and manufacturing of photovoltaic cells utilizing the disclosed technology may be compatible with many semiconductor photovoltaic cell designs. For example, the production flow used for aluminum back surface field (Al-BSF) PV cells and/or passivated emitter and rear contact (PERC) PV cells and/or heterojunction technology (HJT) PV cells, etc. may be adapted, modified, and/or upgraded to produce CVC PV cells such as those described herein. The design, production, and/or manufacturing of the disclosed technology may be compatible with standard and/or existing production and manufacturing lines. The CVCs may be produced and/or manufactured on a post-production basis for many existing production lines. To create a CVC from an existing PV Cell production line, additional and/or less equipment, equipment upgrades, and/or modification of processes/steps may be implemented. The ability to create localized doping that may be needed to create the partitions for a PV cell may be accomplished by adding new equipment or upgrading existing equipment to etch, dope, mask, and/or print the semiconductor wafer/substrate, for example. The etching may be accomplished by laser, chemical etching, plasma etching, scribing, etc. The doping may be accomplished by laser doping, ion implantation with or without masking, epitaxial growth with or without masking, furnace diffusion with/without masking, chemical vapor deposition (CVD) with or without masking, low pressure chemical vapor deposition (LPCVD) with or without masking, screen printing, etc. The masking may be accomplished by photolithography, screen printing, shadow mask, etc. The screen printing may be accomplished by changing the design of the screen to match the desired partition(s) configuration.

For example, the aluminum back surface field photovoltaic cell may be created using a production line for Al-BSF PV cell fabrication. The disclosed technology may be produced on the production line with the addition of a laser tool that may be configured to etch a 2-dimensional pattern commensurate with the desired partition design. The laser tool may be used to scribe/etch the emitter and/or back surface field region to a depth exposing the base/bulk doping and may achieve the semi-electrical isolation of the np junction and/or pp+ junction. For example, such processing may be used to process a wafer without partitions 120 into wafer 100 of FIG. 1. A partition of the Al-BSF cell may include an emitter region 104 that may be separated from a second emitter region 104 by the base semiconductor and/or air and/or insulator 122. The aluminum back surface field region 106 and corresponding aluminum metal layer 112 may be separated from a second aluminum back surface field region 106 and corresponding aluminum metal layer 112 by the base semiconductor and/or air and/or insulator 122. The additional laser scribing tool may be inserted at multiple points in the process flow and/or manufacturing process including, but not limited to, before/after the test/sort step, the metal screen printing step, the phosphorus glass removal step, and/or after the emitter doping step, etc.

Another example of the disclosed technology may be implemented on a bifacial photovoltaic cell that may use boron, aluminum, and/or phosphorus, etc. doping and may be created with the addition of masking and/or etching process steps. FIG. 6 is a cross-sectional view of a semiconductor wafer 700 with cell partitions 120 according to an embodiment of the disclosure. Wafer 700 may be a bifacial PV cell fabricated on a n-type crystalline silicon wafer/substrate 120 with a phosphorus-doped back surface field region 106, a boron-doped emitter region 104, back surface passivation 702, and back capping layer 704. Partitions 120 may be created using a laser scribing tool and/or masking with compatible doping techniques. The masking technique used in conjunction with the doping technique to create partitions 120 may be accomplished by photolithography, screen printing, inkjet, etc. The doping technique used in conjunction with the masking step may create the desired partitions 120.

In embodiments implemented on a bifacial photovoltaic cell, doping may be used to create partitions for a bifacial CVC. For example, doping may be accomplished in conventional furnace diffusion by first adding a protective diffusion mask for boron doping, such as a thermal SiO2 layer, that may be subsequently processed by the application of a screen printed chemical mask with the partition design. A chemical etching step may be used to remove unwanted SiO2 that may have covered the desired regions for the boron emitter. The etching step may be followed by a high temperature boron diffusion step. The diffusion step may be followed by the removal of the masking layers and/or diffusion glass. The masked regions may serve as a diffusion barrier to the boron during the high temperature processing and the unmasked regions may be boron doped. Doping with phosphorus to create the back surface field region may use a similar process flow as the boron doping to create the desired partitions, but replace any boron doping with phosphorus doping. In some embodiments, the phosphorus-doped back surface field region 106 may need an additional masking step to protect the boron emitter characteristics and eliminate/reduce cross doping during phosphorus processing.

Another embodiment of the disclosed technology may be implemented using passivated emitter and rear contact (PERC) photovoltaic cell technology. FIG. 7 is a cross-sectional view of a semiconductor wafer 800 with cell partitions 120 using PERC technology according to an embodiment of the disclosure. Wafer 800 may be similar to wafer 100 except that wafer 800 may include segmented localized back surface field regions 802 comprising a plurality of electrically separate high low junctions 107 per partition 120. A partition 120 of wafer 800 may include an emitter region 104 that may be separated from a second emitter region 104 by the base semiconductor and/or air and/or insulator 122. The localized aluminum back surface field region 802 may be separated from a second localized aluminum back surface field region 802 by the base semiconductor and/or air and/or insulator 122. The localized back surface field 802 and the aluminum metal layer 112 used to form the localized back surface field 802 may align with emitters 104 to form the desired partitions 120.

Similar embodiments may be implemented using many/all semiconductor PV cell architectures including, but not limited to, the emitter wrap through (EWT), interdigitated back contact (IBC), heterojunction thin film (HJT), metal wrap through (MWT), passivated on all sides H-pattern (Pasha), etc. For example, FIG. 8 is a cross-sectional view of a semiconductor wafer 900 with cell partitions using interdigitated back contact (IBC) architecture according to an embodiment of the disclosure. Wafer 900 may be similar to wafer 100 except that wafer 900 may include collectors 104 (and associated bus bars 110) on the back surface, interdigitated with emitters 106, and a front surface field region 902. Each partition 120 may include one pair of interdigitated collector 104 and emitter 106, separated from adjacent pairs by insulator gap 122.

The production and/or manufacturing of CVC(s) may be implemented to provide tester/sorter step compatibility with a parallel configuration using non-CVC technology. Utilizing some embodiments of the disclosed technology, existing manufacturing techniques and production line(s) may be upgraded and/or retrofitted and/or reconfigured to utilize up to 100% of the existing production and/or manufacturing equipment and/or production lines and/or production processes. In order to enable the disclosed technology, simple and low cost changes may be utilized.

For example, some embodiments may allow for the consolidation of process steps used to change a base substrate into a PV cell, such as the consolidation of screen printed steps. In some embodiments, the steps to complete a photovoltaic panel may be consolidated in the PV cell process. For example, consider a stringer/tabber step that may be used by a photovoltaic panel manufacturer to interconnect crystalline silicon PV cells. One embodiment of the technology may allow flexibility in the interconnection step that may be accomplished by screen printing during the PV cell processing. The number of screen printing steps may remain the same/increase/decrease but may allow for module process step simplification. For example, an aluminum back surface field PV cell may have a front screen printed silver step, a back screen printed silver step, and a back screen printed aluminum step but, with the disclosed technology, the three screen printing steps may only have one front silver screen printing step and one back aluminum screen printed step that may allow for the connection of some of the front silver to the back aluminum screen printed metal along the edge of the wafer/substrate.

CVC Panels

The aforementioned wafers (e.g., wafer 100) may be formed into panels. A collection of connected Standard PV Cells and/or CVCs may come in various sizes and shapes and can be referred to as photovoltaic panels, solar panels, solar modules, or photovoltaic modules (hereafter referred to as “panels”). One embodiment of the technology may be a single CVC encapsulated into a panel. The disclosed technology enables configurable power characteristics of a single CVC Panel and may be configured to match the power requirements of electrical devices, equipment, and/or batteries and/or other storage devices.

For example, small electronic devices including, but not limited to, mobile phones, LED lights, and solar battery chargers may require 0.5 watts of power to operate. A single 1 inch square Standard PV Cell can produce this much power, but the cell's approximate 0.5 V output voltage may be insufficient to operate these devices. One embodiment of the disclosed technology (e.g., as described above) may include a single CVC wafer 100 used in a panel that can be configured such that its power characteristics directly meet the requirements of these devices (e.g., so that the panel is tuned to output the required wattage and voltage).

In another example, larger electric or electronic devices including, but not limited to, car battery chargers, televisions, power tool charging, and small refrigerators may require power characteristics of approximately 12 V and 5 watts or more. Standard PV Cells made of 5 or 6 inch pseudo square wafers may provide insufficient voltage to operate these devices directly. Another embodiment of the disclosed technology (e.g., as described above) may include a single CVC wafer used in a panel that can be configured such that its power characteristics directly meet the requirements of these larger devices. For example, 8 inch monocrystalline silicon wafers or large multi-crystalline silicon wafers may be configured with multiple partition CVCs that can produce sufficient power characteristics to directly operate these devices. This embodiment may remove/reduce the need for DC-to-DC converters, increase the useable surface area, reduce the potential points of failure, and reduce the overall costs per unit of power output.

Some embodiments may provide configurable power characteristics on panels of any shape and/or size. By configuring a multitude of partitions, in series and/or parallel, of any shape/size CVC Panel, the disclosed technology may enable the creation of power characteristics such that they match the power characteristics of Standard PV Cells and/or CVC(s). For example, the disclosed technology may enable an installer of residential roof top photovoltaic panels/modules to cover additional roof surface area(s) that are irregular in size or shape (e.g., as illustrated in FIGS. 5A-5B and described above). Another example may allow photovoltaic panels to fill the maximum available space on small, non-uniform surfaces like automobiles and spacecraft while supporting desired power characteristics and/or series/parallel configuration. One embodiment of the disclosed technology may enable the creation of a single wafer with dimensions of 1 meter by 1.6 meters with a multiplicity of partitions, for example.

In some embodiments, panels may include multiple CVCs (e.g., multiple examples of at least one of the wafer cell embodiments described above). The disclosed technology may enable flexibility in the design and configuration of series and/or parallel connection(s) of two or more CVCs, and/or Standard PV Cells. The disclosed technology may enable configurable power characteristics of each CVC and flexibility depending on the series and/or parallel connection(s) to create desired power characteristics and performance of the panel.

For example, a panel may contain 60 six inch pseudo square crystalline silicon photovoltaic cells connected to one another in series with bypass diodes connected in parallel across each of three substrings of 20 PV cells each. In this example, the power characteristics of this panel 1000 may include an output voltage of approximately 33 V and output current of approximately 9 amps. If one or more PV cell(s) are shaded and/or impaired in this configuration, a minimum of 20 PV cells may be bypassed, thereby reducing performance by approximately 33%. Further, shading of only one cell in each of the three substrings of 20 PV cells may result in 100% loss of power and/or performance. One embodiment of the disclosed technology may enable flexibility of design in the connection/interconnection of CVCs to improve panel performance when one or more CVCs are shaded and/or impaired. The disclosed technology may enable flexibility in series and/or parallel substring/string configuration, thereby mitigating performance losses caused by shading and/or impairment of one or more CVCs or standard PV Cells in a panel. Parallel connected CVCs may provide alternative current paths when one or more CVCs in a substring are shaded and/or impaired, for example.

Conditions such as dust in the desert settling to the bottom of a panel, snow settling to the bottom of a panel, and/or any debris or obstruction(s) that accumulate on a panel may impact power characterics of a standard panel by causing the bypass diode to bypass a minimum of 20 cells or such number of cells on the impacted substring. The shading and/or impairment described in this example may result in loss of 33% or more of potential power generated. For example, shading and/or impairment may result in up to a 100% loss impact for portrait installations and/or at least a 33% impact for landscape installations.

Some embodiments may enable a string configuration that may mitigate the impact of shading and/or impairment of one or more CVCs. FIG. 9 is a plan view of a multi-cell panel 1200 with strings 1204 of cells 1202 in parallel according to an embodiment of the disclosure. Using the disclosed technology, a panel 1200 may be configured with 60 six inch CVCs 1202, each producing approximately 3.3 V and approximately 1.5 amps. The CVCs 1020 may be configured in six series substring/strings 1204 of 6. Each string 1204 may have the output voltage of approximately 33 Vs and output current of approximately 1.5 amps. The ten strings 1204 may then be connected/interconnected in parallel to cumulate the output current. Using the disclosed technology as described may mitigate the impact of shading and/or impairment of one or more CVCs. For example, under shading and/or impairment conditions where a substring 1204 is shaded, panel 1200 employing the disclosed technology may only reduce the panel 1200 power output by 10% instead of 33% in a standard panel.

Panel 1200 may enable flexibility in string configuration, in series and/or parallel, to create a wide range of panel power characteristics. For example, if panel power characteristics of approximately 66 V and 4.5 amps are desired, the disclosed technology may enable flexibility of design to achieve these panel power characteristics using 60 CVC(s). In addition, each panel 1200 may be configured with 60 CVC(s) to produce approximately 33 V, 66 V, 99 V, 297 V, etc. and corresponding output current of approximately 9 amps, 4.5 amps, 3 amps, 1 amp, etc. Alternatively, using the disclosed technology, a panel with similar power characteristics may be configured with 36 eight inch CVC(s) each having approximately 33 V, 66 V, 99 V, 297 V, etc. and approximate current output of 9 amp, 4.5 amps, 3 amps, and 1 amp etc.

As described below, one or more panels 1200 may be used together in systems (e.g., system 1700 of FIG. 14 described below). Some embodiments may simplify the design, construction, and/or operation of panels by reducing/eliminating added electronics needed for a functioning and/or optimized and/or efficient photovoltaic energy system (“PV System”). Common electronics for photovoltaic systems may include, but are not limited to, bypass diodes, blocking diodes, optimizers, charge controllers, DC-to-DC converters, DC-to-AC inverters, micro-inverters, inverters, Max Power Point Trackers, batteries, fuel cells, etc. including other electrical devices employed in a PV System after collection of power from panels. (“auxiliary electronics”).

FIG. 10 is a plan view of a multi-cell panel 1300 with cell details 1302, 1304 according to an embodiment of the disclosure. This embodiment may replace standard PV Cells by panel 1300 with CVCs that produce an output voltage of 1.65 V each. In this example configuration, the CVCs in each of the 3 substrings may be wired in series according to detail 1302 or 1304 such that each of the sub strings has a output voltage of 33 V. Thus, if one or more CVCs are impaired, the output voltage may remain approximately 33 V. Substrings may be connected/interconnected in parallel to achieve desired power characteristics. The parallel design enabled by the disclosed technology may provide independent paths for current flow if any one or more cells becomes impaired and may thus reduce and/or eliminate the need for bypass diodes.

Some embodiments may include increasing the number of substrings/strings on a panel. Each additional substring, connected in parallel, may decrease the power loss when a single CVC becomes impaired. For example, a panel may contain 4 substrings. Each substring may contain 15 CVCs with approximately 2.2 V output voltage each and connected in series for a substring output of approximately 33 V. These four substrings may be wired in parallel to provide desired power characteristics, all with a reduction of, or elimination of, the need for bypass diodes. In this configuration, a single impaired CVC may only reduce panel power output by 25% instead of 33%. Additional examples may include, but are not limited to, 5 substrings of 12 CVCs whose output voltage is approximately 2.75 V; 6 substrings of 10 CVs whose output voltage is approximately 5.5 V; 60 CVCs having approximately 33 V each, all connected in parallel.

Some embodiments of the disclosed technology may enable flexibility in string configuration to avoid known shading and/or impairment conditions. For example, consider an installation of two or more panels where one panel may cause shading of the adjacent panel(s). Panels may be installed with enough space between them to mitigate one panel shading one or more adjacent panels. Using the disclosed technology, strings may be designed to mitigate the impact of shading while maintaining desired panel power characteristics. This embodiment of the disclosed technology may enable greater density of panels and more power production.

Some embodiments of the disclosed technology may enable flexibility in string configuration to avoid known shading and/or impairment conditions. For example, consider an installation of one or more panels on a rooftop where known shading conditions such as a chimney, trees, light pole, or other predictable shade occurs during some period of time. If a standard panel experiences this known shading condition, a minimum of one string of 20 PV Cells may be impacted at any one time. The disclosed technology may enable flexibility of string configuration to produce better power characteristics under identical shading conditions. The disclosed technology may enable the design and configuration of rooftop and other panel installations to include surface areas that have shading and/or impairment conditions that may not be practicable or viable otherwise.

Another embodiment of the disclosed technology may enable flexibility in string configuration to avoid unknown shading and/or impairment conditions, for example the shading and/or impairment caused by complete failure of a one or more PV Cells or CVCs. Should a single PV Cell in a standard panel become completely shaded and/or impaired because of breakage, mechanical failure, or complete obstruction by a leaf or bird droppings, etc., the entire series string of 20 PV Cells may be bypassed. Some embodiments of the disclosed technology may enable flexibility in CVC(s) string configuration such that the shading and/or impairment of any one CVC may have limited impact on other non-shaded and/or impaired CVC(s). For example, using the disclosed technology, a panel could be configured with 60 CVCs each having a voltage of 33 V and 0.15 amps all connected/interconnected in parallel. In this configuration, the shading and/or impairment of any one CVC may not impact the power characteristics of any other non-shaded or non-impaired CVC. Similarly, using the disclosed technology, a panel may be configured with 60 CVC(s) configured into 20 parallel connected strings of 3 CVC(s), each CVC producing approximately 11 V and 0.45 amps. In this example, the loss of any one cell on any string may impact only the two additional CVC(s) on that string. The disclosed technology may enable flexibility to configure any number of CVC(s) on a series and/or parallel string and creates flexibility of a wide combination of CVC and panel power characteristics. This may reduce and/or eliminate the need for bypass diodes and/or other auxiliary electronics.

Some embodiments may mitigate the risk and severity of hot spots. Hotspot generation may occur under non-uniform external stimulus, such as partial shading and/or impairment, where one or more PV cells in a string are impacted, thus causing reverse bias operation. This reverse bias may be driven by the difference in output current for a photovoltaic cell in a series connected/interconnected string. When a PV cell is in reverse bias it may undergo reverse bias breakdown, creating extraordinary heat or a hotspot. Hotspots may negatively impact the power characteristics of a PV cell and may cause thermal events such as fire, melting, delamination, etc. Some embodiments may mitigate the likelihood of, and the impact of, hotspots. By creating higher voltage output and lower current output on a CVC, hotspots caused by a partial and/or complete impairment/shading event may be mitigated by having a smaller difference in output current generated by a fully illuminated CVC and the shaded and/or impaired CVC. For example, complete shading and/or impairment of one PV Cell in the standard panel 1000 may decrease the current output from that PV Cell from 9 amps to 0 amps, resulting in a change of 9 amps. Some embodiments may enable flexibility in power characteristics of CVC(s) such that a CVC may have 3.3 V and 1.5 amps. Should this CVC within a panel (e.g., panel 1200) be completely shaded and/or impaired, the output current may be reduced to 0 amps or a change of 1.5 amps. In this example, the disclosed technology may reduce the change in output current on a cell in reverse bias from 9 amps to 1.5 amps, thereby reducing the risk of a hotspot and increasing the safety and performance of the CVC and/or panel. Some embodiments may enable flexibility of string configuration in a panel and may reduce the risk and/or severity of hotspots by enabling a greater number of substrings/strings, each containing fewer CVC(s), while maintaining desired panel power characteristics.

Some embodiments may enable the creation of single CVC panel roof shingles. The disclosed technology may enable high voltage output shingles that may be connected in parallel, thereby simplifying design and installation, reducing installation costs including labor and materials, reducing impact of shading and/or impairment, reducing the potential points of failure, reducing engineering and design costs, and increasing the roof surface that may be utilized. By reducing the number of shingles in series, the impact of shading and/or impairment of any single CVC may be reduced/mitigated, as described above.

FIG. 11 is a diagram of a roof shingle 1400 according to an embodiment of the disclosure. Some embodiments may enable the configuration of partitions 1420 on a single CVC roof shingle 1400 such that one portion of the CVC shingle 1400 may be shaded or impaired without impacting or impairing the non-shaded region of the CVC shingle 1400. For example, in FIG. 11, each half of the substrate produces 2.75 volts independently, therefore any impairment on either the left or right side would only impact half of the CVC cell in the roof shingle 1400. Some embodiments of the disclosed technology may increase the flexibility of substrate/wafer size and shape used in a roof shingle with configurable power characteristics. These embodiments may enable design and configuration of shingles that have enhanced power characteristics in partially shaded and/or obstructed/impaired conditions such as the shade or overlapping of an adjacent shingle. The disclosed technology may mitigate the impact of, and need for replacement of, any damaged or impaired CVC shingle 1400 that is connected in a parallel substring/string configuration.

Some embodiments may enable enhanced flexibility in matching the power characteristics of a panel or a number of panels with external loads including auxiliary electronics. For example, one or more panels may be connected/interconnected with power inverters commonly used for DC to AC power conversion These inverters, and/or other auxiliary electronics, may require incoming power characteristics such as 12 V, 600 V, 1000 V, 1500 V, etc. Some embodiments may provide flexibility in the design and configuration of panels to meet the power characteristics of auxiliary electronics. By using higher voltage output CVCs to increase the output voltage of a panel, the desired power characteristics of an inverter, and/or auxiliary electronics, may be achieved using fewer higher voltage panels.

For example, FIG. 12 is a plan view of a multi-cell panel 1500 with cell details 1502, and FIG. 13 is a plan view of a multi-cell panel 1600 with cell details 1602, according to embodiments of the disclosure. The example panel 1500 of FIG. 12 may include 5 series connected strings with 12 crystalline silicon wafer 6″ pseudo squares with power characteristics of 66 volts and 0.9 amps for each series connected string of 12 substrates. The 5 series connected strings may be connected in parallel to each other to yield panel power characteristics of 66 volts and 4.5 amps. The example panel 1500 of FIG. 12 may reduce the number of required panels for some installations by half by using panels 1500 with output voltages of 66V instead of the traditional 33V. The example panel 1600 of FIG. 13 may include 18 partitions and power characteristics of output voltage of 9.9 volts and output current of 0.5 amps. 60 substrates/wafers may be series connected to produce power characteristics of output voltage of 594 V and output current of 0.5 amps. The example panel 1600 of FIG. 13 may have an output voltage of approximately 600 V. Panels 1600 may be wired in parallel (e.g., up to the maximum power for which the inverter is designed). In this configuration, any number of panels 1600 may be used because each panel 1600 may be sufficient to power the inverter. Additional 600 V panels 1600 may be added in parallel any time after the system is installed without having to redesign or replace the inverter and/or other auxiliary electronics.

To reduce the impact of impaired cell(s), such as cells that become impaired through mechanical failure or optical obstruction thereby increasing resistance and reducing current flow, some photovoltaic system configurations may include auxiliary electronics like bypass diodes, optimizers, and micro-inverters. However, some embodiments described herein may reduce the impact of impaired cell(s) without these auxiliary electronics. FIG. 14 is a diagram of a multi-panel system 1700 according to an embodiment of the disclosure. In system 1700, each panel 1702 may include CVCs 1704 with 18 partitions and power characteristics of output voltage of 9.9 volts and output current of 0.5 amps (e.g., so that 6 parallel strings of 10 CVCs 1704 connected in series may produce power characteristics of output voltage of 99 V output current of 0.5 amps (99 volts and 3 amps in total)). There may be 4 parallel strings of CVC PV panels 1702 with 4 series connected panels 1702 to produce power characteristics of output voltage 397 V and 12 amps in total for the system 1700 to output to inverter 1706. This configuration may provide multiple paths for current to flow through each panel 1702 even if one or more CVCs 1704 become impaired. As long as one substring remains unimpaired, the panel 1702 may not impair the current flow between other panels 1702 and may reduce and/or eliminate the need for optimizers, micro-inverters, and/or other auxiliary electronics. Even in the event of a damaged CVC 1704 and/or panel 1702 (e.g., with permanent damage, not mere shading), system 1700 may continue to function.

Additionally, because output voltage can be set to provide any required power characteristics, system 1700 output may be fed to a load without DC to DC converters, for example. In some embodiments, max power point tracking may be optimized by performing tracking at the individual substrate/photovoltaic cell level. The disclosed technology may allow for higher voltage per PV cell such that max power point tracking on a per PV cell basis may be enabled. In some embodiments, ideal max power point tracking may involve optimizing performance for photovoltaic systems at the individual PV cell level. Using the disclosed technology, performance for photovoltaic systems may be enabled at the individual PV cell and/or CVC level then the impact of non-ideal external/internal factors may be limited to the particular impacted PV cell and/or CVC while potentially limiting the overall system impact. In addition, the complexity of the max power point tracking for some PV systems may be designed to account for both a variable voltage and variable current. The added complexity for the electrical component to adjust and optimize for power considering both voltage and current may add challenges including but not limited to cost, complexity, failure points, etc. The disclosed technology may allow for a simplification in max power point tracking over a wide range of illumination by performing voltage optimization as the dominant control factor. The voltage behavior for PV cells under various levels of illumination may have a relatively tight range relative to the change in illumination level. A 90% change in illumination may only change the voltage output of a photovoltaic cell less than 10% compared to a roughly proportional 90% change in electrical current.

The production and manufacturing of photovoltaic panels utilizing with the disclosed technology may be compatible with many and/or all existing photovoltaic panel production technologies. The disclosed technology may be adapted and/or upgraded and/or modified into photovoltaic panel production lines including but not limited to 3 bus bar, 4 bus bar, 5 bus bar, etc., multi-wire, multi-bus, smart wire, back contact, etc. to produce PV panels with CVCs connected in series and/or parallel to produce configurable power characteristics. To create a CVC PV Panel from an existing PV Panel production line, additional and/or less equipment, equipment upgrades and/or modification of processes/steps may be implemented. The ability to connect and/or interconnect CVCs may be accomplished by adding new equipment and/or upgrading existing equipment to tab, string, encapsulate, laminate, frame, test, etc. an existing production line while maintaining the ability to reuse common and/or existing equipment. The tabbing may be accomplished using any equipment and soldering techniques available in industry. The stringing may be accomplished according to the desired power characteristics so that the electric current follows the photovoltaic generator path and not alternative electrical paths including but not limited to allowing a wafer to function as diode, transistor, etc. The encapsulation may be accomplished using any encapsulation processing. The lamination may be accomplished using any lamination processing. For example, the disclosed technology may enable common PV panel processing including crystalline silicon PV cells in a string, ethyl-vinyl-acetate (EVA) covers on the sunny side and non-sunny side of a collection of CVCs, a top coverglass, a Tedlar film-PET (TPT) backsheet, and common aluminum framing. However, the CVCs string interconnection/connection may be upgraded/adjusted/modified to match new/different string architectures compatible with the disclosed technology.

For example, a 5 bus bar PV panel production line may be adjusted/upgraded/modified to produce 60 CVCs on six inch pseudo square wafers in series and/or parallel circuits. Some/most of the processing steps may remain unchanged for the CVCs circuit compared with common PV cell series circuits. However, the connection/interconnection with the disclosed technology may allow alternative electrical circuit options and may utilize stringer/tabber modifications to accommodate the new electrical architectures. The CVCs may be formed using one and/or more than one interconnection/connection point between physically isolated wafers. In addition, the individual CVCs may have interconnections/connections of partitions on the same wafer and may reduce/eliminate the number of interconnections/connections between physically isolated wafers and thus may implement stringer/tabber functionality that may or may not be available on common equipment.

FIG. 15 is a plan view of a multi-cell panel 1800 with cell details 1802 according to an embodiment of the disclosure. In this example, each CVC 1802 may have 9 partitions and power characteristics of output voltage of 4.95 V and output current of 1 amps. 60 substrates/wafers may be series connected in panel 1800 to produce power characteristics of output voltage of 297 V and output current of 1 amp. As a production consideration, the interconnection/connection path may be configured to flow completely through a first CVC 1802 with an output voltage of 4.95 V before connecting to a second CVC 1802 also with 4.95 V. The interconnection for the first CVC 1802 to the second CVC 1802 may be designed to eliminate any undesired current paths and may be limited to one wire connection between two physically isolated wafers and directed on an exit partition on a first wafer interconnected/connected to second wafer entrance partition. In some embodiments, panel 1800 may be manufactured with auxiliary electronics added to enable the configurable power characteristics to be selected post production by the customer (e.g., such that the auxiliary electronics may enable the selection of output voltage and output current). Some embodiments may allow the CVC PV panel to have power characteristics that may enable the use of thinner wires to support the decreased output current compared to existing PV panels.

In some embodiments, the disclosed technology may take advantage of the change in electrical current flow for a photovoltaic interconnected/connected substring/string. The reduction/change in electrical current may simplify the number and location of the connection/interconnection between two physically isolated substrates. Other potential embodiments may take advantage of locating the point of interconnection/connection between two physically isolated samples in a designed location. For example, consider a string of 6 inch pseudo square p-type crystalline silicon substrates that have angled/“chamfered” corner edges that may otherwise be consider non-active solar absorbing regions to be the location of the conductor/wire/etc. that may be used to connect/interconnect neighboring substrates/wafers and thereby may alleviate some stress points that may be caused by a limited space normally allowed for the connection/interconnection.

Additional CVC Systems and Examples

Due to the configurations described above, panels may be placed relatively close to one another, because shading of one panel by an adjacent panel may not result in a total failure of the shaded panel, as described above. For single-axis tracking panel sets, for example, panels may tilt throughout the day to track the sun, and may be placed close together and shade one another as the sun moves without significant loss in overall system output and/or efficiency.

The disclosed technology may address several issues specific to solar panels used in outer space applications, including, but not limited to, the following examples: total weight of power generation system, reducing potential points of failure, mitigating the performance impact of potential point of failure, and simplicity of design with known subsystems. Photovoltaic systems on spacecraft may have rigid requirements for reliability because they are difficult to access, repair, and/or replace. CVCs may have options to be wired in parallel reducing the impact from any impaired cell, as described above. Furthermore, the disclosed technology may reduce the need for auxiliary electronics (e.g., which may add weight and/or failure points to space-based systems), may increase the overall lifetime of space-based systems, and/or may reduce the design, production, operation, and/or maintenance costs of such systems.

Electric vehicles may use PV Cells for many purposes including, but not limited to, maintaining batteries when disconnected from grid power, providing additional electric power while driving, and/or running air conditioning or heating while vehicles are unoccupied. Electrical vehicles using PV cells may benefit from the disclosed technology in several ways. First, vehicles may have non-uniform surface areas that may take advantage of CVCs made in any shape and/or size that may cover the largest percentage of a vehicle's available surface area. Second, some design considerations may require a consistent voltage output regardless of environmental lighting conditions including direct axis, partial shading, and low illumination levels. As discussed above, CVCs may generate any output voltage and may be connected in parallel to reduce the impact of the previously mentioned constraints. Furthermore, the disclosed technology may reduce the need for auxiliary electronics (e.g., which may add weight and/or failure points to vehicle-based systems), may increase the overall lifetime of vehicle-based systems, and/or may reduce the design, production, operation, and/or maintenance costs of such systems.

Some embodiments may enable a panel(s) to be designed with CVC(s) in both series and/or parallel connections/interconnections with power characteristics that may be manually or automatically reconfigured. For example, consider a 60 CVC panel with 6 strings of 10 series connected CVC(s) as described above. The connection(s)/interconnection may be designed and manufactured such that the configured CVC(s) can be changed. For example, FIG. 16 shows plan views of multi-cell panels 1900A/1900B with cell details 1902, and FIG. 17 shows plan views of multi-cell panels 2000A/2000B with cell details 2002, according to embodiments of the disclosure. In FIG. 16, CVC panels 1900A/1900B with 10 series connected strings with 6 crystalline silicon wafers 6″ pseudo squares with power characteristics of 33 volts and 0.9 amps for each series connected string with 6 substrates are shown. The 10 series connected strings when connected in parallel to each other may have panel power characteristics of 33 volts and 9 amps in panel 1900A, while. another embodiment may have panel power characteristics of 66 volts and 4.5 amps as shown in panel 1900B. In FIG. 17, CVC panels 2000A/2000B with 10 series connected strings with 6 crystalline silicon wafers 6″ pseudo squares with power characteristics of 33 volts and 0.9 amps for each series connected string with 6 substrates are shown. The 10 series connected strings when connected in parallel to each other may have panel power characteristics of 33 volts and 9 amps in panel 2000A. Another embodiment may have panel power characteristics of 165 volts and 1.8 amps as shown in panel 2000B.

As shown in the panels 1900A/1900B/2000A/2000B, the string configuration of the panel may be converted or reconfigured to change the connection/interconnection by and/or between any CVC and/or substring/string. This re-configuration may be achieved with a manual mechanical switch or electric circuit switching, for example. The re-configuration of cells and/or substrings may be manually selected or selected/controlled by a computer/processor, for example. In some embodiments, a processor/computer may receive data from a CVC and/or panel indicating shading or partial/complete impairment of one of more CVC's and may automatically re-configure the parallel and series connection(s) of CVC(s) on a panel to enhance, improve, or mitigate the power characteristics of the panel. In some embodiments, a processor and/or computer may receive data from a CVC and/or panel indicating shading or partial/complete impairment of one of more CVCs and may automatically change the parallel and series connection(s) by and between CVC(s) and/or substrings/strings on any given panel with CVC(s) and/or strings in parallel and/or series on another panel.

Residential installation may have historically been constrained by design constraints including, but not limited to, the size of the inverter and the required operating voltage. An inverter may require an operational threshold for the voltage input and power input of the DC power that may then be converted into AC power. The disclosed technology may allow increased flexibility in the installation expandability and/or standardized inverters. For example, residential inverters may be standardized to 8 kWs, and by using the disclosed technology with configurable power characteristics, a smaller subset of CVC PV panels may be used to operate auxiliary electronics and allow options for expansion.

Power distribution and power consumption may use a fixed voltage with an electrical current proportional to electrical load supply and/or consumption. High voltage transmission lines may utilize various amounts of electrical current to supply customers according to demand but may use a fixed high voltage. Similarly, the operation of an electrical system in homes, buildings, factories, etc. may be supplied at 120 VAC. Photovoltaic cells may produce a fixed voltage and the electrical current may fluctuate with illumination level. However, a series string of photovoltaic cells may have a large change in both current and voltage depending on the circuit design of series connected photovoltaic cells compared with parallel connected photovoltaic cells. The disclosed technology may enable flexibility for photovoltaic cells to be connected in parallel and thereby improve the voltage stability and allow the change in performance to be dominated by changes in electrical current. So called power smoothing may prefer a more consistent voltage performance and may better tolerate swings in electrical current.

FIGS. 18A and 18B are cross-sectional views of thin film panels 2100 and 2101 according to an embodiment of the disclosure. The aforementioned partitioning may be applied to thin film panels 2100 as shown. Photovoltaic power generation is the direct conversion of light (radiation) into electrical power. Conventional crystalline silicon based photovoltaic cells are the most common substrate used to produce photovoltaic energy and may be considered first generation technology. Other semiconductor materials that are wafer based may also be considered first generation technology. Thin film photovoltaic cells may be considered second generation technologies and represent a significant part of the commercial photovoltaic industry and include, but are not limited to, amorphous silicon, cadmium tellurium (CdTe), copper indium gallium selenide (CIGS), etc. Thin film cells may follow the same photovoltaic principles as wafer based technologies but may involve different base material characteristics and production techniques. The disclosed technology described herein applied to first generation or wafer based technologies may also be designed with partitions and configurable power characteristics using thin film PV cells. For example, thin film panel 2100 may include glass layer 2102, transparent conduction oxide (TCO) layer 2106, n-CdS layer 2106, p-CdTe layer 2108, buffer layer (e.g., an intrinsic undoped layer of CdTe or an oxide) 2110, and back contact layer (e.g., TCO or metallic conductor) 2112. To form partitions in a manner similar to the silicon embodiments disclosed above, TCO layer 2106, n-CdS layer 2106, and back contact layer 2112 may be electrically separated by insulating gap 2114, while p-CdTe layer 2108 may provide a common base layer. For embodiments wherein buffer layer 2110 is an insulator, buffer layer 2110 may be continuous. However, in some embodiments, buffer layer 2110 may be a semiconductor or a conductor. Thin film panel 2101 provides an example wherein buffer layer 2110 is a semiconductor or a conductor. In this case, buffer layer 2110 may be partitioned by insulating gap 2114.

Thin film cells may share many/all of the same benefits and/or configurations disclosed in this technology subject to the constraints of thin film production processes. As an example, once a photon in a thin film PV cell is absorbed (similar to a crystalline silicon PV cell) the electron-hole pair may be directed by an electric field to be gathered as electrical power. The disclosed technology may be applied to thin film photovoltaic panels such that partitions may be created to configure the power characteristics. Consider the light collection current as a vertical current flow that is then transported by the connecting electrical circuit. One embodiment of the disclosed technology may implement a thin film photovoltaic cell to incorporate an electrically preferred path for the cathode and the anode such that there exist a layer sandwiched between the cathode and anode to allow for a semi-electrical isolation with a contiguous layer connecting to the partitions (e.g., see FIG. 18). In an analogous manner, third generation photovoltaic cells including, but not limited to, organic photovoltaic cells, organometallic cells, quantum cells, graphene, etc. may also benefit from the disclosed technology when the electrical circuit is designed to establish a preferred electrical path after the collection of photons into electrical current.

While various embodiments have been described above, it should be understood that they have been presented by way of example and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope. In fact, after reading the above description, it will be apparent to one skilled in the relevant art(s) how to implement alternative embodiments. For example, other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Accordingly, other implementations are within the scope of the following claims.

In addition, it should be understood that any figures which highlight the functionality and advantages are presented for example purposes only. The disclosed methodology and system are each sufficiently flexible and configurable such that they may be utilized in ways other than that shown.

Although the term “at least one” may often be used in the specification, claims and drawings, the terms “a”, “an”, “the”, “said”, etc. also signify “at least one” or “the at least one” in the specification, claims and drawings.

Finally, it is the applicant's intent that only claims that include the express language “means for” or “step for” be interpreted under 35 U.S.C. 112(f). Claims that do not expressly include the phrase “means for” or “step for” are not to be interpreted under 35 U.S.C. 112(f). 

1. A photovoltaic cell comprising: a substrate configured as a single light absorption region; a plurality of first semiconductor regions arranged on or in the substrate and physically separated from one another, each first semiconductor region forming one of a plurality of collecting junctions with the single light absorbing region; and a plurality of second semiconductor regions arranged on or in the substrate and physically separated from one another and from each of the plurality of first semiconductor regions, each second semiconductor region forming one of a plurality of high-low junctions with the single light absorbing region, wherein each of the first semiconductor regions forms at least one separate cell partition with at least one of the second semiconductor regions, thereby forming a plurality of cell partitions on or in the substrate.
 2. The photovoltaic cell of claim 1, further comprising at least one interconnect electrically coupling the first semiconductor region of at least one of the cell partitions to the second semiconductor region of at least one separate one of the cell partitions.
 3. The photovoltaic cell of claim 2, wherein the at least one interconnect electrically couples at least two of the cell partitions to one another in series.
 4. The photovoltaic cell of claim 2, wherein a total voltage output of the photovoltaic cell is determined by an arrangement of the at least one interconnect.
 5. The photovoltaic cell of claim 1, further comprising at least one interconnect electrically coupling at least two of the cell partitions to one another in parallel.
 6. The photovoltaic cell of claim 1, further comprising: at least one first interconnect electrically coupling at least two of the cell partitions to one another in series; and at least one second interconnect electrically coupling at least two of the cell partitions to one another in parallel.
 7. The photovoltaic cell of claim 1, wherein at least one of the plurality of first semiconductor regions and plurality of second semiconductor regions is a doped region of the substrate.
 8. The photovoltaic cell of claim 1, wherein at least one of the plurality of first semiconductor regions and plurality of second semiconductor regions is an epitaxial layer on the substrate.
 9. The photovoltaic cell of claim 1, further comprising at least one first conductive contact arranged on the substrate and configured to facilitate electrical connection with at least one of the plurality of first semiconductor regions.
 10. The photovoltaic cell of claim 1, further comprising at least one second conductive contact arranged on the substrate and configured to facilitate electrical connection with at least one of the plurality of second semiconductor regions.
 11. The photovoltaic cell of claim 1, wherein: the substrate comprises a p type material; each of the plurality of first semiconductor regions comprises an n+ type material; and each of the plurality of second semiconductor regions comprises a p+ type material.
 12. The photovoltaic cell of claim 1, further comprising at least one coating covering at least a portion of the plurality of first semiconductor regions.
 13. The photovoltaic cell of claim 12, wherein the at least one coating includes an anti-reflective coating.
 14. The photovoltaic cell of claim 12, wherein the at least one coating includes an insulator material.
 15. The photovoltaic cell of claim 1, further comprising at least one contact covering at least a portion of the plurality of second semiconductor regions.
 16. The photovoltaic cell of claim 15, wherein the at least one contact includes aluminum.
 17. The photovoltaic cell of claim 15, wherein the at least one contact is in electrical contact with a plurality of the second semiconductor regions.
 18. The photovoltaic cell of claim 1, wherein: the substrate includes a front side and a back side; the plurality of first semiconductor regions are arranged on or in the front side of the substrate; and the plurality of second semiconductor regions arranged on or in the back side of the substrate.
 19. The photovoltaic cell of claim 1, wherein: the substrate includes a front side and a back side; the plurality of first semiconductor regions are arranged on or in the back side of the substrate; and the plurality of second semiconductor regions arranged on or in the back side of the substrate.
 20. The photovoltaic cell of claim 1, wherein the plurality of first semiconductor regions are physically separated from one another.
 21. The photovoltaic cell of claim 1, wherein the plurality of second semiconductor regions are physically separated from one another.
 22. The photovoltaic cell of claim 1, wherein the substrate has a surface area greater than 36 square inches.
 23. The photovoltaic cell of claim 1, wherein the substrate has a surface that is not square-shaped. 